Laptop wirless connected but browser not working!

Out of the blue my wireless connection stopped working, my browser cannot connect, I don't know what to do. I have a Samsung laptop that's running on Windows 7. I thought it was the browser so I installed the Internet Explorer 9 and while doing so it was able to download the updates but when I open up the browser it still doesn't work.

I'm thinking that it might be a network problem but I've ran out of ideas. I have a netgear router that's connecting a desktop computer, two VOIP devices, my sisters Mac works but we have two laptop that aren't working. I've also tried connecting it directly to an ethernet cable from the router but it's still not able to open the browser.

Please help, my next move is to just save everything and completely reboot it.

Thanks for all your replies, I really appreciate it. For some odd reason I turned the laptop on this morning to follow the tips here and as I opened the browser the internet started working again. It's very strange but if it ever happens again I'll try what was posted here. Thanks.